This proposed program is to provide selected cannabinoids from the several classes that occur in Cannabis, screen the selected compounds for intraocular pressure-lowering effects and to perform further studies to develop the best cannabinoid for the treatment of open-angle glaucoma. The program involves the development of sources of supplies needed in pre-clincal animal studies and also for the clinical investigations. This proposal will provide suitable dosage form and supporting animal data for the clinical studies but not the clinical investigations per se. Within this program are planned studies of selected cannabinoids for their effects on aqueous humor dynamics and on ocular blood pressure and ocular blood flow. Effects of these compounds on systemic blood pressure and central nervous system functions will be ascertained by general pharmacologic methodology and by injection into the third ventricle.